Department of Food Science and Human Nutrition, University of Illinois , 905 South Goodwin Avenue, Urbana, Illinois 61801, United States.
Abbott Nutrition , 3300 Stelzer Road, Columbus, Ohio 43219, United States.
J Agric Food Chem. 2017 May 24;65(20):4184-4192. doi: 10.1021/acs.jafc.7b00851. Epub 2017 May 12.
Galactooligosaccharides (GOS) are bifidogenic and lactogenic prebiotics; however, GOS utilization is strain-dependent. In this study, commercially available bifidobacteria and lactobacilli probiotic strains were evaluated for growth in the presence of GOS. Several bifidobacteria and lactobacilli grew on GOS; however, the specific GOS oligomers utilized for growth differed. A subset of probiotic bifidobacteria and lactobacilli revealed three different GOS utilization profiles delineated by the degrees of polymerization (DP) of GOS: (1) utilization of 2 DP GOS, (2) utilization of ≤3 DP GOS, and (3) utilization of all DP GOS. Specifically, Lactobacillus acidophilus NCFM (LA_NCFM) was found to efficiently consume all GOS oligomers. Extracellular β-galactosidase activity in the cell-free supernatant of LA_NCFM correlated with accumulation of galactose. In a LacL-deficient LA_NCFM strain, GOS utilization was abolished. This is the first report of LacL's role in GOS metabolism in LA_NCFM. In vitro GOS utilization should be considered when GOS are delivered with probiotic bifidobacteria and lactobacilli.
半乳糖寡糖（GOS）是双歧因子和生乳因子的益生元；然而，GOS 的利用取决于菌株。在这项研究中，评估了市售双歧杆菌和乳杆菌益生菌菌株在 GOS 存在下的生长情况。一些双歧杆菌和乳杆菌可以在 GOS 上生长；然而，用于生长的特定 GOS 低聚物不同。益生菌双歧杆菌和乳杆菌的一部分显示出三种不同的 GOS 利用谱，由 GOS 的聚合度 (DP) 来区分：(1) 利用 2 DP GOS，(2) 利用 ≤3 DP GOS，和 (3) 利用所有 DP GOS。具体来说，发现嗜酸乳杆菌 NCFM（LA_NCFM）能够有效地消耗所有 GOS 低聚物。LA_NCFM 细胞外无细胞上清液中的β-半乳糖苷酶活性与半乳糖的积累相关。在 LacL 缺陷型 LA_NCFM 菌株中，GOS 的利用被废除。这是首次报道 LacL 在 LA_NCFM 中 GOS 代谢中的作用。当 GOS 与益生菌双歧杆菌和乳杆菌一起输送时，应该考虑 GOS 的体外利用。
